A pivot-hung door drive system, said door drive system comprising:
- a door frame;
- a pivot-hung door being connected to said door frame;
- a door actuation lever being configured and disposed to permit pivoting of said pivot hung door;
- a pivot-hung door drive system;
- one of said pivot-hung door and said door frame having a chamber;
- said pivot-hung door drive system being disposed in said chamber and comprising:
- an electro-mechanical drive unit;
- said electro-mechanical drive unit being operable to pivot said pivot-hung door alternatively in an opening direction or in a closing direction;
- said electro-mechanical drive unit comprising:
- a drive motor;
- a power transmission unit;
- said power transmission unit comprising:
- a rotatable drive screw;
- said rotatable drive screw having an axis and a screw thread extending along said axis of said drive screw;
- a toothed rack;
- said toothed rack comprising a plurality of gear teeth and a screw thread for receiving said screw thread of said drive screw, with said plurality of gear teeth extending sequentially axially of said drive screw;
- said drive motor being operatively connected to said drive screw to permit rotation of said drive screw, alternatively in one rotational direction or in an opposite rotational direction, to effect movement of said toothed rack, in one of two opposite axial directions of said drive screw to pivot said door in said opening direction or in said closing direction;
- a door position control shaft;
- said door position control shaft having an axis and a plurality of gear teeth extending away from and about said axis of said door position control shaft;
- said door position control shaft being mountable with its axis in a fixed position;
- said gear teeth of said door position control shaft being configured and disposed to be in mesh with said gear teeth of said toothed rack to permit rotation of said door position control shaft around said axis of said door position control shaft upon movement of said toothed rack in either axial direction of said drive screw;
- and
- said door position control shaft being connected to said door actuator lever to pivot said pivot-hung door during rotation of said door position control shaft;
- said toothed rack being non-rotatably mounted with respect to said axis of said drive screw;
- at least one mounting plate;
- said toothed rack being configured and disposed to be mounted on said at least one mounting plate;
- said at least one mounting plate comprising at least one guide recess;
- said toothed rack comprising at least one guide lug;
- and
- said at least one guide recess being configured and disposed to receive said at least one guide lug to hold said toothed rack non-rotatably about said axis of said drive screw.